In recent years, there has been a substantial increase in the use and deployment of wireless client devices, from dual-mode smartphones to laptop computers to tablets capable of operating in accordance with a particular Institute of Electrical and Electronics Engineers (IEEE) standard. With “wireless” becoming the de-facto medium for connectivity among users, it has become increasingly important for network systems to intelligently manage connections.
In some embodiments, multiple controllers (e.g., network coordination devices) may jointly serve a common area. Accordingly, a client may obtain network connectivity by exchanging network traffic with one or more of the controllers via an access point. In a cluster controller environment wherein a plurality of controllers communicates amongst the cluster in order to share network information, including state information of the client devices connected to the network as well as the access points within the control scope of the cluster of controllers, a primary controller of a client device may handle the network traffic of the client device and a standby controller of the client device may handle the network traffic of the client device when the primary controller of the client device enters an inactive state, or as a result of load balancing. Similarly, a primary controller of an access point may handle the network traffic of the access point and a standby controller of the access point may handle the network traffic of the access point when the primary controller of the access point enters an inactive state, or as a result of load balancing.
Today, wireless communication networks often include a form of network security requiring a client device to present authentication information during an authentication process prior to obtaining access to the network. The authentication process may include establishing one or more encryption keys to encrypt and decrypt network traffic transmitted to and received from the client device. For example, a wireless communication network may implement a Wired Equivalent Privacy (WEP) security algorithm requiring the client device to present a proper encryption key.
When a client device connects to a communication network, an access point is the first network device with which the client device exchanges information. While the client device remains stationary, it remains associated with the same access point and does not expect a disturbance in its connectivity. However, when the primary controller of the client device fails, the encryption key established during the authentication process is lost. Therefore, a new encryption key must be established which typically requires deauthenticating the client device and re-authenticating the client device.
When a client device undergoes a de-authentication and re-authentication process, all current session information is lost including, for example, all secure shell (SSH) sessions, all file transfer protocol (FTP) sessions, all audio or video communications, etc. Additionally, some client devices include logic that, upon receiving a certain number of de-authentication notifications from an access point, the client device may attempt to associate with a different access point, which may not be beneficial to the wireless communication network and/or the client device.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.